using bsoncxx::builder::stream::document;
using bsoncxx::builder::stream::open_document;
using bsoncxx::builder::stream::close_document;
using bsoncxx::builder::stream::open_array;
using bsoncxx::builder::stream::close_array;
using bsoncxx::builder::stream::finalize;

So... I'm not sure why the tutorial material doesn't work for me, nor do I fully understand the typing, templating, or brace initializer lists of C++. And while I'd be happy to go through a tutorial specific to the issue I'm having, I'm not even sure what to Google for. Knowledge gaps are too broad. =P